Stenotic lesions form on the lumen walls of blood vessels to create narrowings that restrict blood flow through the vessel, and may comprise a hard, calcified substance and/or a softer thrombus material. Interventional catheterization procedures such as balloon angioplasty, stent deployment, atherectomy, and thrombectomy are well known and have proven effective in the treatment of such stenotic lesions. Such modalities require the passage of a therapy catheter through a patient's vasculature and into a targeted branch vessel.
Recently, a variety of devices have been developed to address atheroembolization, which is the obstruction of blood vessels by stenotic debris released during interventional catheterization therapies such as those mentioned above. Distal protection devices (DPDs) such as filters and occluders represent one class of intravascular devices that can be used to prevent atheroembolization. A filter mounted on a guidewire or a catheter may be positioned distally of a stenosis to capture and remove potentially embolic debris without causing hemostasis during use of the filter. Alternatively, an occluder device may be positioned distally of a stenosis to temporarily stop the flow of blood, including any stenotic debris that may have become entrained in the blood. The contaminated blood is aspirated from the treated area before the distal occluder device is collapsed to permit resumption of blood flow.
Occlusion devices may also be placed proximally of a stenosis to provide so-called proximal protection. Proximal occlusion devices may be used alone to prevent atheroembolization, or they may be used in conjunction with a distal occluder to form an isolated treatment chamber about the stenosis to be treated. Preliminary deployment of a proximal occlusion device may be advantageous in preventing atheroembolization because advancing a treatment catheter, a guidewire or a DPD into a stenosis can dislodge particulate debris, even before the stenosis is being opened. Proximal occlusion can create temporary hemostasis in the vessel to prevent distal embolization by debris created during crossing and/or treatment of the lesion. As is done with distal occlusion, contaminated blood is aspirated from the treated area before the proximal occluder device is collapsed to permit resumption of blood flow.
Known occluder devices typically employ an inflatable occlusion balloon or a mechanically expandable occluder element with their attendant expansion apparatuses. For a proximal occlusion device such as a guiding catheter, an occlusion balloon requires an inflation lumen extending around or alongside a main lumen to provide fluid actuation of the balloon from the proximal end of the catheter. A guiding catheter having a mechanically expandable occluder typically requires a slidable sleeve or push/pull wire for mechanical actuation of the occluder from the proximal end of the catheter. Adding an extra lumen or additional actuator features to a guiding catheter disadvantageously require the outside diameter to be larger, and/or the inside diameter of the main lumen to be smaller. Thus, a need exists for a guiding catheter having an atheroembolization prevention system that does not require increasing the wall thickness of the guiding catheter. Such a guiding catheter should be operable simply and quickly during interventional catheterization procedures. Other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims taken in conjunction with the accompanying drawings.